Comparison and screening of prostate cancer stem cells isolation methods / 中国组织工程研究

BACKGROUND: Prostate cancer stem cell is an important reason for the invasion and recurrence of prostatic carcinoma. However, separation efficiency of prostate cancer stem cells is very low.OBJECTIVE: To explore the efficient method for isolating and identifying the prostate cancer stem cells from human prostatic carcinoma cell lines PC-3 and LNCap. METHODS: Prostate cancer cell lines PC-3 and LNCap were cultured in serum free medium (SFM) and serum supplemented medium (SSM), respectively. The percentage of prostate cancer stem cells from different medium was detected by flow cytometry through markers CD133 and CD44, and the properties of prostate cancer stem cells were preliminarily identified using inducing differentiation experiments.RESULTS AND CONCLUSION: PC-3 and LNCap formed sphere cells in SFM, which can be induced into adherent cells after culture in SSM. Higher percentage of CD44+/CD133+cells was obtained from LNCap cells (1.71%; 0.73%) than PC-3 cells (0.59%; 0.32%) in both SFM and SSM. The number of CD44+/CD133+ LNCap cells was more than PC-3 using both methods (P 0.05). However, the culture cycle was longer and number of obtained cells was less by SFM culture, directly influencing functional determination of prostate cancer stem cells. Compared with suspension culture method with SFM, SSM is more convenient and effective in isolating prostate cancer stem cells from LNCap cells.

Effect of TNF-α on production and activation of caspase-3 in primary rat renal proximal tubule cells / 中国病理生理杂志

AIM:To investigate the production and activation of caspase-3 in primary rat renal proximal tubule cells in response to tumor necrosis factor-α(TNF-α) and the implication of nuclear factor-κB (NF-κB) in the process. METHODS:Isolated rat renal proximal tubule cells (PTCs) from male adult Sprague Dawley rats were treated with TNF-α according to the indicated time courses. A specific NF-κB inhibitor,Bay11-7082,was used alone or as a pretreatment for 1 h followed by exposure to TNF-α for 24 h.The protein levels of cleaved caspase-3,caspase-3,I-κBα,phosphorylated I-κBα,and GAPDH were detected by Western blotting using specific antibodies. RESULTS:The protein level of cleaved caspase-3 relative to caspase-3 was significantly increased in the presence of TNF-α for 6 h,12 h,and 24 h. Protein levels of caspase-3 were significantly decreased by 12 h and returned to baseline by 24 h in the presence of TNF-α. Treatment with Bay11-7082 for 25 h alone or pretreatment with Bay11-7082 for 1 h followed by addition of TNF-α for 24 h caused a remarkable reduction in both cleaved caspase-3 and caspase-3 as compared to control and TNF-α treated groups. An increase in phosphorylated I-κBα was observed from 15 min to 60 min after treatment with TNF-α at a dose of 10 μg/L in PTCs. CONCLUSION:NF-κB is not only associated with the activation of caspase-3 but also the production of caspase-3 in primary rat renal proximal tubule cells in response to TNF-α.

Differentiation of human embryonic stem cells into cardiomyocytes in vitro / 中国组织工程研究

BACKGROUND: Differentiation of embryonic stem (ES) cells into cardiomyocytes in vitro has been studied in great detail in the world. However, much of what is currently known about cardiomyocyte differentiation from ES cells has been learned from studies on mouse in China, few studies are on human ES cells.OB JECTIVE: To investigate the differentiation effcacy of human ES cells into functional cardiomycytes with the human H14 ES cell line.DESIGN: Suspending method was used to form pseudo-embryo proper of human ES cells so as to observe ratio of pseudo-embryo proper with rhythmic contraction and expression of specific gene of myocardium in various differentiated phases.SETTING: Molecular Biology Laboratory of Stanley Ho Center for Emerging Infectious Diseases, School of Public Health, the Chinese University of Hong Kong.MATERIALS: Human ES cell line H14 was obtained from WiCell Research Institute (Wisconsin, USA) with a license agreement.METHODS: The experiments were carried out in the Molecular Biology Laboratory of Stanley Ho Center for Emerging Infectious Diseases, School of Public Health, the Chinese University of Hong Kong from August to December of 2006.The H14 ES cell colony was used to form embryoid bodies (EBs) by using suspending method. Four days later,pseudo-embryo proper was cultured in gelatin-coating 6-well culture plate (5-10 embryo proper/well) and spontaneously differentiated into moving pseudo-embryo proper. Rhythmic contraction was observed under microscope and RT-PCR was used to detect expression of special genes of myocardium.MAIN OUTCOME MEASURES: Ratio of pseudo-embryo proper with rhythmic contraction and expression of specific gene of myocardium in various differentiated phasesRESULTS: Spontaneously contracting cells appeared as cluster and were identified in approximately 2% of EBs at differentiation day 8 and increased to as many as 10% of the EBs by day 16. The beating rate of contracting cells arranged at 70-100 beats per minute. RT-PCR analyses demonstrated that cells isolated from spontaneous beating areas within the EB expressed the cardiac transcription factors GATA-4 and Nkx2.5, cardiac progenitor gene Isl-1 and cardiomyocyte marker gene α-MHC.CONCLUSION: This is the first time to report human ES cells can effectively differentiate into functional cardiomyocytes in China.

Association between HBV infection and HLA-DPB1 gene in population of Guangzhou Chinese / 中国病理生理杂志

AIM: To investigate the association between HBV infection and HLA-DPB1 gene in population of Guangzhou Chinese. METHODS: 58 unrelated patients (test positive of HbsAg,HBeAg,HbcAb) and 75 unrelated healthy control individuals were typed by sequencing based typing (SBT) method in their HLA-DPB1 gene. RESULTS: The phenotype frequencies of HLA-DPB1 alleles of patients and control have no significant difference. CONCLUSION: These results indicate that there is no association between HLA-DPB1 gene and HBV infection.